Parasitic protozoa are the cause of numerous diseases in humans and domestic livestock. Frequently, glycoconjugates on the cell surface of these organisms play a crucial role in determining parasite survival and infectivity. Over the past decade it has become clear that many of these molecules are anchored into the plasma membrane via GPI (glycosylphosphatidyl inositol) anchors. For example, numerous studies have indicated that the function of the trypanosome VSG (variant surface glycoprotein) is to provide a uniform protective coat over virtually the entire surface of the organism, with no enzymatic or detectable receptor-like activity. This glycoprotein barrier protects the parasite from the host's non-specific immune system; parasites lacking a VSG coat are rapidly killed by the alternate complement system. However, some of the parasitic protozoa, particularly those belonging to the kinetoplastidae such as Leishmania, have been found to synthesize a number of exotic GPI-related structures which are not attached to proteins. These structures are termed lipophosphoglycans (LPGs). In collaboration with Dr. Sam Turco, who heads one of the world's foremost centers for the study of Leishmania, we have set out to determine the structure, conformation, and dynamics of Leishmania LPG. We have just begun to investigate, by NMR spectroscopy, the carbohydrate structure of Leishmania donovani LPG and some of its enzymatically and chemically generated fragments. A 6-(H2PD4)-b-Galp1-4Manp disaccharide obtained from the phosphoglycan portion of LPG was assigned by NMR as a model compound for the intact phosphoglycan. The latter was then assigned using similar methodology, which included 2D 1H- and 13C-NMR experiments.